We're supplying two years of free weather forecasts with each poster. We pay a small amount for every weather forecast requested by a poster. After this free two year period, it will be $7.50 USD per year. This is less about making money and more about building a sustainable business in the long term. We will have a web page set up nearer the time, which will allow you to 'top up'.
Of course there any many places on the internet to find the weather for free, this is possible due to government backing or advertising. It is a mammoth task for our weather information provider to sustain a huge ever-changing database of all the different weather conditions, in all of the different places in the world. When we call upon their database, they have no way of making advertising revenue. Hence, we have to pay a very small amount each time. The poster checks in with the database every hour (during the day) to make sure it has the most recent forecast, so over a year you can see how this adds up.